Hydrogen is a colorless and odorless gas with the lowest density of all the gases. There is evidence suggesting that hydrogen could become a clean fuel source, and it is used to power some buses and cars. In the chemical industry it is used to produce ammonia as a fertilizer, and it removes sulfur during oil production. In addition, it hydrogenates oils to produce fats like margarine.

Other common uses for hydrogen include filling balloons and airships, as well as forming a protective environment during glass sheet manufacturing. As hydrogen reacts with oxygen to produce water, it can become problematic when used in airships and balloons.

In the human body hydrogen exists to form hydrogen bonds. However, it is not chemically active in other ways. As well as being common on Earth, hydrogen is found elsewhere in the solar system. For example, Jupiter is primarily made from hydrogen.